A microRNA array reveals extensive regulation of microRNAs during brain development

MicroRNA regulation in neural tube defects: Insights into pathogenesis and potential therapeutic targets

Neural tube defects (NTDs) represent a significant burden on global pediatric health, contributing to high rates of infant mortality and morbidity. Despite extensive research into their etiology, NTDs continue to pose challenges in diagnosis and treatment. MicroRNAs (miRNAs) have emerged as promising candidates for understanding the molecular mechanisms underlying NTDs and potentially offering avenues for improved diagnosis and therapeutic intervention. This review explores the multifaceted roles of miRNAs in the context of NTD pathogenesis. Studies have identified specific miRNA profiles associated with NTDs, providing insights into their potential as diagnostic biomarkers. Furthermore, dysregulation of certain miRNAs has been implicated in the pathophysiology of NTDs, highlighting their role as potential therapeutic targets. Additionally, animal models and deep sequencing approaches have expanded our understanding of the diverse miRNA expression patterns associated with NTDs. By unraveling the intricate molecular mechanisms underlying NTD pathogenesis, miRNAs offer promising avenues for early detection and intervention, ultimately improving outcomes for affected individuals.

Critical analysis of descriptive microRNA data in the translational research on cardioprotection and cardiac repair: lost in the complexity of bioinformatics

The unsuccessful translation of cardiac regeneration and cardioprotection from animal experiments to clinical applications in humans has raised the question of whether microRNA bioinformatics can narrow the gap between animal and human research outputs. We reviewed the literature for the period between 2000 and 2024 and found 178 microRNAs involved in cardioprotection and cardiac regeneration. On analyzing the orthologs and annotations, as well as downstream regulation, we observed species-specific differences in the diverse regulation of the microRNAs and related genes and transcriptomes, the influence of the experimental setting on the microRNA-guided biological responses, and database-specific bioinformatics results. We concluded that, in addition to reducing the number of in vivo experiments, following the 3R animal experiment rules, the bioinformatics approach allows the prediction of several currently unknown interactions between pathways, coding and non-coding genes, proteins, and downstream regulatory elements. However, a comprehensive analysis of the miRNA-mRNA-protein networks needs a profound bioinformatics and mathematical education and training to appropriately design an experimental study, select the right bioinformatics tool with programming language skills and understand and display the bioinformatics output of the results to translate the research data into clinical practice. In addition, using in-silico approaches, a risk of deviating from the in vivo processes exists, with adverse consequences on the translational research.

MYC regulation of the miR-92-Robo1 axis in Slit-mediated commissural axon guidance

In the developing spinal cord, translational repression of Robo1 expression by microRNA-92 (miR-92) in precrossing commissural axons (CAs) inhibits Slit/Robo1-mediated repulsion facilitating commissural axon projection and midline crossing; however, the regulatory mechanisms governing miR-92 expression in the developing commissural neurons are currently lacking. Here, we propose that the transcription factor MYC regulates miR-92 expression in the developing spinal cord (of either sex) to control Robo1 levels in precrossing CAs, modulating Slit/Robo1-mediated repulsion and midline crossing. MYC, miR-92, and Robo1 are differentially expressed in the developing chicken spinal cord. MYC binds to the promoter region upstream of the gga-miR-92 gene in vitro. MYC knockdown dramatically decreases miR-92 expression and increases chicken Robo1 (cRobo1) levels. In contrast, overexpression of MYC significantly induces miR-92 expression and reduces cRobo1 levels. MYC knockdown or overexpression results in significant inhibition or induction of miR-92 activity in the developing chicken spinal cord, respectively. Disruption of the MYC-dependent regulation of the miR-92-cRobo1 axis affects Slit2-mediated CA growth cone collapse in vitro and impairs CA projection and midline crossing in vivo. These results elucidate the role of the MYC-miR-92-cRobo1 axis in Slit2/Robo1-mediated CA repulsion and midline crossing.

Green chemistry: Modern therapies using nanocarriers for treating rare brain cancer metastasis from colon cancer

Brain metastasis (BM) from colon cancer is associated with a poor prognosis and restricted treatment alternatives, largely due to issues related to blood-brain barrier (BBB) permeability and the negative effects of standard chemotherapy. Nanotechnology improves treatment efficacy by enabling targeted and controlled drug delivery. This review article evaluates the potential of nanotechnology-based therapies for treating colon cancer BM, emphasizing their capacity to cross the BBB, diminish metastatic growth, and enhance overall survival rates. A review of multiple studies evaluated nanoparticles (NPs) as carriers for chemotherapy, focusing on parameters including particle size, surface charge, and drug-loading capacity. The study also reviewed studies that examined BBB penetration, in vitro tumor accumulation, and in vivo tumor growth inhibition. In vitro findings indicated that NPs accumulate more efficiently in BM tissue than in healthy brain tissue and show significant BBB penetration. In vivo, nanotherapy markedly inhibited tumor growth and prolonged survival relative to conventional chemotherapy or control treatments while also exhibiting reduced side effects. Recent studies demonstrated that plant extracts can effectively and safely synthesize nanomaterials, positioning them as a viable and environmentally friendly precursor for nanomaterial production. Nanotechnology-based therapies demonstrate significant potential in the treatment of colon cancer BM by minimizing systemic toxicity, enhancing therapeutic efficacy, and facilitating more targeted drug delivery. Further research is required to confirm these findings and implement them in clinical practice.

Resveratrol Upregulates miR-124-3p Expression to Target DAPK1, Regulating the NLRP3/Caspase-1/GSDMD Pathway to Inhibit Pyroptosis and Alleviate Spinal Cord Injury

Currently, an effective treatment for spinal cord injury (SCI) is not available. Due to the irreversible primary injury associated with SCI, the prevention and treatment of secondary injury are very important. In the secondary injury stage, pyroptosis exacerbates the deterioration of the spinal cord injury, and inhibiting pyroptosis is beneficial for recovery from SCI. The aim of this study was to clarify the role of resveratrol (RES) and the antipyroptotic mechanisms of RES and miR-124-3p in SCI to lay a theoretical foundation for the clinical treatment of SCI and provide new therapeutic approaches. Using cell staining and related molecular protein detection techniques to assess DAPK1, the effects of miR-124-3p and RES on pyroptosis were investigated, and the effects of RES on injured spinal cord repair in rats were evaluated using tissue staining and related functional recovery experiments. In vitro, DAPK1 interacts with NLRP3, exerting a pyroptotic effect through the NLRP3/Caspase-1/GSDMD pathway and DAPK1 knockdown inhibits pyroptosis. miR-124-3P negatively regulates the level of DAPK1 and reduced cell pyroptosis. RES increased miR-124-3p expression and reduces DAPK1 expression, affecting the NLRP3/Caspase-1/GSDMD pathway and inhibiting pyroptosis. In vivo, RES reduces GSDMD-N levels in rats with SCI, promotes functional recovery, and thus promotes recovery from SCI. Therefore, we concluded that RES increases the level of miR-124-3p, which targets DAPK1, regulates the NLRP3/Caspase-1/GSDMD pathway, inhibits pyroptosis and alleviates SCI.

NACC2, a molecular effector of miR-132 regulation at the interface between adult neurogenesis and Alzheimer's disease

The generation of new neurons at the hippocampal neurogenic niche, known as adult hippocampal neurogenesis (AHN), and its impairment, have been implicated in Alzheimer's disease (AD). MicroRNA-132 (miR-132), the most consistently downregulated microRNA (miRNA) in AD, was recently identified as a potent regulator of AHN, exerting multilayered proneurogenic effects in adult neural stem cells (NSCs) and their progeny. Supplementing miR-132 in AD mouse brain restores AHN and relevant memory deficits, yet the exact mechanisms involved are still unknown. Here, we identify NACC2 as a novel miR-132 target implicated in both AHN and AD. miR-132 deficiency in mouse hippocampus induces Nacc2 expression and inflammatory signaling in adult NSCs. We show that miR-132-dependent regulation of NACC2 is involved in the initial stages of human NSC differentiation towards astrocytes and neurons. Later, NACC2 function in astrocytic maturation becomes uncoupled from miR-132. We demonstrate that NACC2 is present in reactive astrocytes surrounding amyloid plaques in mouse and human AD hippocampus, and that there is an anticorrelation between miR-132 and NACC2 levels in AD and upon induction of inflammation. Unraveling the molecular mechanisms by which miR-132 regulates neurogenesis and cellular reactivity in AD, will provide valuable insights towards its possible application as a therapeutic target.

MicroRNA-455-3P as a peripheral biomarker and therapeutic target for mild cognitive impairment and Alzheimer's disease

MicroRNAs are small non-coding RNAs evolutionary conserved molecules. They regulate cellular processes, including RNA silencing, post-translational gene expression and neurodegeneration. MicroRNAs are involved with human diseases such as cancer, Alzheimer's disease (AD) and others. Interestingly, cerebrospinal fluids (CSF) and the blood of AD patients have altered expressions of many RNAs, which may serve as potential peripheral biomarkers. The intensive investigation from our lab revealed that microRNA-455-3 P (miR-455-3p) is a strong candidate as a potential biomarker and therapeutic target for AD. Several genes implicated in the pathogenesis of AD are directly targeted by miR-455-3p. Several years of our lab research revealed that miR-455-3p regulates important physiological processes associated with AD, such as the processing of the amyloid precursor protein (APP), TGF-β signaling, the regulation of oxidative stress, mitochondrial biogenesis, and synaptic damages. The expression of miR-455-3p in mild cognitive impaired subjects and AD patients pointed out its involvement in AD progression. Recently, our lab generated both transgenic and knockout mice for miR-455-3p. Interestingly miR-455-3p transgenic mice showed superior cognitive learning, improved memory and extended lifespan compared to age matched wild-type mice, whereas miR-455-3-p knockout mice showed cognitive decline and reduced lifespan. Information derived from mouse models further demonstrated the advantageous impact of miR-455-3p on dendritic growth, synaptogenesis, and mitochondrial biogenesis in preventing the onset and progression of AD. The identification of miR-455-3p as a biomarker was suggested by its presence in postmortem AD brains, B-lymphocytes, and fibroblasts. Our hypothesis that miR-455-3p could be a peripheral biomarker and therapeutic target for AD.

Circulating miR-30e-3p induces disruption of neurite development in SH-SY5Y cells by targeting ABI1, a novel biomarker for schizophrenia

Schizophrenia (SCZ) represents a set of enduring mental illnesses whose underlying etiology remains elusive, posing a significant challenge to public health. Previous studies have shown that the neurodevelopmental process involving small molecules such as miRNA and mRNA is one of the etiological hypotheses of SCZ. We identified and verified that miR-30e-3p and ABI1 can be used as biomarkers in peripheral blood transcriptome sequencing data of patients with SCZ, and confirmed the regulatory relationship between them. To further explore their involvement, we employed retinoic acid (RA)-treated SH-SY5Y differentiated cells as a model system. Our findings indicate that in RA-induced SH-SY5Y cells, ABI1 expression is up-regulated, while miR-30e-3p expression is down-regulated. Functionally, both miR-30e-3p down-regulation and ABI1 up-regulation promote apoptosis and inhibit the proliferation of SH-SY5Y cells. Subsequently, the immunofluorescence assay detected the expression location and abundance of the neuron-specific protein β-tubulinIII. The expression levels of neuronal marker genes MAPT, TUBB3 and SYP were detected by RT-qPCR. We observed that these changes of miR-30e-3p and ABI1 inhibit the neurite growth of SH-SY5Y cells. Rescue experiments further support that ABI1 silencing can correct miR-30e-3p down-regulation-induced SH-SY5Y neurodevelopmental defects. Collectively, our results establish that miR-30e-3p's regulation of neurite development in SH-SY5Y cells is mediated through ABI1, highlighting a potential mechanism in SCZ pathogenesis.

Posttranscriptional regulation of FAN1 by miR-124-3p at rs3512 underlies onset-delaying genetic modification in Huntington's disease

Many Mendelian disorders, such as Huntington's disease (HD) and spinocerebellar ataxias, arise from expansions of CAG trinucleotide repeats. Despite the clear genetic causes, additional genetic factors may influence the rate of those monogenic disorders. Notably, genome-wide association studies discovered somewhat expected modifiers, particularly mismatch repair genes involved in the CAG repeat instability, impacting age at onset of HD. Strikingly, FAN1, previously unrelated to repeat instability, produced the strongest HD modification signals. Diverse FAN1 haplotypes independently modify HD, with rare genetic variants diminishing DNA binding or nuclease activity of the FAN1 protein, hastening HD onset. However, the mechanism behind the frequent and the most significant onset-delaying FAN1 haplotype lacking missense variations has remained elusive. Here, we illustrated that a microRNA acting on 3'-UTR (untranslated region) SNP rs3512, rather than transcriptional regulation, is responsible for the significant FAN1 expression quantitative trait loci signal and allelic imbalance in FAN1 messenger ribonucleic acid (mRNA), accounting for the most significant and frequent onset-delaying modifier haplotype in HD. Specifically, miR-124-3p selectively targets the reference allele at rs3512, diminishing the stability of FAN1 mRNA harboring that allele and consequently reducing its levels. Subsequent validation analyses, including the use of antagomir and 3'-UTR reporter vectors with swapped alleles, confirmed the specificity of miR-124-3p at rs3512. Together, these findings indicate that the alternative allele at rs3512 renders the FAN1 mRNA less susceptible to miR-124-3p-mediated posttranscriptional regulation, resulting in increased FAN1 levels and a subsequent delay in HD onset by mitigating CAG repeat instability.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

The role of microRNAs in the pathophysiology of human central nervous system: A focus on neurodegenerative diseases

microRNAs (miRNAs) are suggested to play substantial roles in regulating the development and various physiologic functions of the central nervous system (CNS). These include neurogenesis, cell fate and differentiation, morphogenesis, formation of dendrites, and targeting non-neural mRNAs. Notably, deregulation of an increasing number of miRNAs is associated with several neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and CNS tumors. They are particularly known to affect the amyloid β (Aβ) cleavage and accumulation, tau protein homeostasis, and expression of alpha-synuclein (α-syn), Parkin, PINK1, and brain-derived neurotrophic factor (BDNF) that play pivotal roles in the pathogenesis of neurodegenerative diseases. These include miR-16, miR-17-5p, miR-20a, miR-106a, miR-106b, miR-15a, miR-15b, miR-103, miR-107, miR-298, miR-328, miR-195, miR-485, and miR-29. In CNS tumors, several miRNAs, including miR-31, miR-16, and miR-21 have been identified to modulate tumorigenesis through impacting tumor invasion and apoptosis. In this review article, we have a look at the recent advances on our knowledge about the role of miRNAs in human brain development and functions, neurodegenerative diseases, and their clinical potentials.

Identification of miR-128 Target mRNAs That Are Expressed in B Cells Using a Modified Dual Luciferase Vector

MicroRNAs (miRNAs) are 21-25 nucleotide long non-coding ribonucleic acids that modulate gene expression by degrading transcripts or inhibiting translation. The miRNA miR-128, originally thought to be brain-specific, was later also found in immune cells. To identify a valuable immune cell model system to modulate endogenous miR-128 amounts and to validate predicted miR-128 target mRNAs in B cells, we first investigated miR-128 expression using Northern blot analysis in several cell lines representing different stages of B cell development. The results showed that only primary brain cells showed significant levels of mature miR-128. To study the function of miR-128 in immune cells, we modified dual luciferase vectors to allow easy transfer of 3' UTR fragments with predicted miR-128 binding sites from widely used single to dual luciferase vectors. Comparison of in silico predicted miR-128-regulated mRNAs in single and dual luciferase constructs yielded similar results, validating the dual luciferase vector for miRNA target analysis. Furthermore, we confirmed miR-128-regulated mRNAs identified in silico and in vivo using the Ago HITS-CLIP technique and known to be expressed in B cells using the dual luciferase assay. In conclusion, this study provides new insights into the expression and function of miR-128 by validating novel target mRNAs expressed in B cells and identifying additional pathways likely controlled by this miRNA in the immune system.

Addictive drugs modify neurogenesis, synaptogenesis and synaptic plasticity to impair memory formation through neurotransmitter imbalances and signaling dysfunction

Drug abuse changes neurophysiological functions at multiple cellular and molecular levels in the addicted brain. Well-supported scientific evidence suggests that drugs negatively affect memory formation, decision-making and inhibition, and emotional and cognitive behaviors. The mesocorticolimbic brain regions are involved in reward-related learning and habitual drug-seeking/taking behaviors to develop physiological and psychological dependence on the drugs. This review highlights the importance of specific drug-induced chemical imbalances resulting in memory impairment through various neurotransmitter receptor-mediated signaling pathways. The mesocorticolimbic modifications in the expression levels of brain-derived neurotrophic factor (BDNF) and the cAMP-response element binding protein (CREB) impair reward-related memory formation following drug abuse. The contributions of protein kinases and microRNAs (miRNAs), along with the transcriptional and epigenetic regulation have also been considered in memory impairment underlying drug addiction. Overall, we integrate the research on various types of drug-induced memory impairment in distinguished brain regions and provide a comprehensive review with clinical implications addressing the upcoming studies.

Exploring the impact of miR-128 in inflammatory diseases: A comprehensive study on autoimmune diseases

microRNAs (miRNAs) play a crucial role in various biological processes, including immune system regulation, such as cell proliferation, tolerance (central and peripheral), and T helper cell development. Dysregulation of miRNA expression and activity can disrupt immune responses and increase susceptibility to neuroimmune disorders. Conversely, miRNAs have been shown to have a protective role in modulating immune responses and preventing autoimmunity. Specifically, reducing the expression of miRNA-128 (miR-128) in an Alzheimer's disease (AD) mouse model has been found to improve cognitive deficits and reduce neuropathology. This comprehensive review focuses on the significance of miR-128 in the pathogenesis of neuroautoimmune disorders, including multiple sclerosis (MS), AD, Parkinson's disease (PD), Huntington's disease (HD), epilepsy, as well as other immune-mediated diseases such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). Additionally, we present compelling evidence supporting the potential use of miR-128 as a diagnostic or therapeutic biomarker for neuroimmune disorders. Collectively, the available literature suggests that targeting miR-128 could be a promising strategy to alleviate the behavioral symptoms associated with neuroimmune diseases. Furthermore, further research in this area may uncover new insights into the molecular mechanisms underlying these disorders and potentially lead to the development of novel therapeutic approaches.

Maternal immune activation and role of placenta in the prenatal programming of neurodevelopmental disorders

Maternal infection during pregnancy, leading to maternal immune activation (mIA) and cytokine release, increases the offspring risk of developing a variety of neurodevelopmental disorders (NDDs), including schizophrenia. Animal models have provided evidence to support these mechanistic links, with placental inflammatory responses and dysregulation of placental function implicated. This leads to changes in fetal brain cytokine balance and altered epigenetic regulation of key neurodevelopmental pathways. The prenatal timing of such mIA-evoked changes, and the accompanying fetal developmental responses to an altered in utero environment, will determine the scope of the impacts on neurodevelopmental processes. Such dysregulation can impart enduring neuropathological changes, which manifest subsequently in the postnatal period as altered neurodevelopmental behaviours in the offspring. Hence, elucidation of the functional changes that occur at the molecular level in the placenta is vital in improving our understanding of the mechanisms that underlie the pathogenesis of NDDs. This has notable relevance to the recent COVID-19 pandemic, where inflammatory responses in the placenta to SARS-CoV-2 infection during pregnancy and NDDs in early childhood have been reported. This review presents an integrated overview of these collective topics and describes the possible contribution of prenatal programming through placental effects as an underlying mechanism that links to NDD risk, underpinned by altered epigenetic regulation of neurodevelopmental pathways.

microRNA-132 regulates gene expression programs involved in microglial homeostasis

microRNA-132 (miR-132), a known neuronal regulator, is one of the most robustly downregulated microRNAs (miRNAs) in the brain of Alzheimer's disease (AD) patients. Increasing miR-132 in AD mouse brain ameliorates amyloid and Tau pathologies, and also restores adult hippocampal neurogenesis and memory deficits. However, the functional pleiotropy of miRNAs requires in-depth analysis of the effects of miR-132 supplementation before it can be moved forward for AD therapy. We employ here miR-132 loss- and gain-of-function approaches using single-cell transcriptomics, proteomics, and in silico AGO-CLIP datasets to identify molecular pathways targeted by miR-132 in mouse hippocampus. We find that miR-132 modulation significantly affects the transition of microglia from a disease-associated to a homeostatic cell state. We confirm the regulatory role of miR-132 in shifting microglial cell states using human microglial cultures derived from induced pluripotent stem cells.

Studies on the application of single-stranded DNA and PNA probes for electrochemical detection of miRNA 141

The abnormal concentration of microRNAs (miRNAs) can be associated with occurrence of various diseases including cancer, cardiovascular and neurodegenerative, hence they can be considered as potential biomarkers. An attractive approach could be the application of electrochemical methods, particularly where hybridization event between single-stranded deoxyribonucleic acid (ssDNA) or peptide-nucleic acid (PNA) with miRNA strand happens. Recently, the use of various nanomaterials such as gold nanoparticles, graphene oxide, quantum dots as well as catalyzed hairpin assembly or hybridization chain reaction were proposed to further enhance the performance of elaborated sensors. Herein, we present the studies on selection of receptor layer composition for detection of miRNA 141. The possibility of formation of receptor layer and further duplex monolayer between ssDNA or PNA with miRNA was analyzed by atomic force microscopy (AFM) technique. The interaction of ssDNA and PNA probes with miRNA was further verified using surface plasmon resonance (SPR) and quartz - crystal microbalance (QCM) techniques. On the basis of impedance spectroscopy it was shown that the use of unlabelled ssDNA as receptor layer provided 0.1 pM detection limit. This shows that proposed biosensor that is simple in preparation and use is an attractive alternative to other recently presented approaches.

The Role of miR-128 in Neurodegenerative Diseases

Several neurodegenerative disorders are characterized by the accumulation of misfolded proteins and are collectively known as proteinopathies. Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) represent some of the most common neurodegenerative disorders whose steady increase in prevalence is having a major socio-economic impact on our society. Multiple laboratories have reported hundreds of changes in gene expression in selective brain regions of AD, PD, and HD brains. While the mechanisms underlying these changes remain an active area of investigation, alterations in the expression of noncoding RNAs, which are common in AD, PD, and HD, may account for some of the changes in gene expression in proteinopathies. In this review, we discuss the role of miR-128, which is highly expressed in mammalian brains, in AD, PD, and HD. We highlight how alterations in miR-128 may account, at least in part, for the gene expression changes associated with proteinopathies. Indeed, miR-128 is involved, among other things, in the regulation of neuronal plasticity, cytoskeletal organization, and neuronal death, events linked to various proteinopathies. For example, reducing the expression of miR-128 in a mouse model of AD ameliorates cognitive deficits and reduces neuropathology. Overall, the data in the literature suggest that targeting miR-128 might be beneficial to mitigate the behavioral phenotype associated with these diseases.

The miR-124-AMPAR pathway connects polygenic risks with behavioral changes shared between schizophrenia and bipolar disorder

Schizophrenia (SZ) and bipolar disorder (BP) are highly heritable major psychiatric disorders that share a substantial portion of genetic risk as well as their clinical manifestations. This raises a fundamental question of whether, and how, common neurobiological pathways translate their shared polygenic risks into shared clinical manifestations. This study shows the miR-124-3p-AMPAR pathway as a key common neurobiological mediator that connects polygenic risks with behavioral changes shared between these two psychotic disorders. We discovered the upregulation of miR-124-3p in neuronal cells and the postmortem prefrontal cortex from both SZ and BP patients. Intriguingly, the upregulation is associated with the polygenic risks shared between these two disorders. Seeking mechanistic dissection, we generated a mouse model that upregulates miR-124-3p in the medial prefrontal cortex. We demonstrated that the upregulation of miR-124-3p increases GRIA2-lacking calcium-permeable AMPARs and perturbs AMPAR-mediated excitatory synaptic transmission, leading to deficits in the behavioral dimensions shared between SZ and BP.

The landscape of exosomal non-coding RNAs in breast cancer drug resistance, focusing on underlying molecular mechanisms

Breast cancer (BC) is the most common malignancy among women worldwide. Like many other cancers, BC therapy is challenging and sometimes frustrating. In spite of the various therapeutic modalities applied to treat the cancer, drug resistance, also known as, chemoresistance, is very common in almost all BCs. Undesirably, a breast tumor might be resistant to different curative approaches (e.g., chemo- and immunotherapy) at the same period of time. Exosomes, as double membrane-bound extracellular vesicles 1) secreted from different cell species, can considerably transfer cell products and components through the bloodstream. In this context, non-coding RNAs (ncRNAs), including miRNAs, long ncRNAs (lncRNAs), and circular RNAs (circRNAs), are a chief group of exosomal constituents with amazing abilities to regulate the underlying pathogenic mechanisms of BC, such as cell proliferation, angiogenesis, invasion, metastasis, migration, and particularly drug resistance. Thereby, exosomal ncRNAs can be considered potential mediators of BC progression and drug resistance. Moreover, as the corresponding exosomal ncRNAs circulate in the bloodstream and are found in different body fluids, they can serve as foremost prognostic/diagnostic biomarkers. The current study aims to comprehensively review the most recent findings on BC-related molecular mechanisms and signaling pathways affected by exosomal miRNAs, lncRNAs, and circRNAs, with a focus on drug resistance. Also, the potential of the same exosomal ncRNAs in the diagnosis and prognosis of BC will be discussed in detail.

Therapeutic Implications of microRNAs in Depressive Disorders: A Review

MicroRNAs are hidden players in complex psychophysical phenomena such as depression and anxiety related disorders though the activation and deactivation of multiple proteins in signaling cascades. Depression is classified as a mood disorder and described as feelings of sadness, loss, or anger that interfere with a person’s everyday activities. In this review, we have focused on exploration of the significant role of miRNAs in depression by affecting associated target proteins (cellular and synaptic) and their signaling pathways which can be controlled by the attachment of miRNAs at transcriptional and translational levels. Moreover, miRNAs have potential role as biomarkers and may help to cure depression through involvement and interactions with multiple pharmacological and physiological therapies. Taken together, miRNAs might be considered as promising novel therapy targets themselves and may interfere with currently available antidepressant treatments.

Update on Findings about Sudden Sensorineural Hearing Loss and Insight into Its Pathogenesis

Sudden sensorineural hearing loss (SSNHL) is routinely encountered and is one of the most common emergent diseases in otolaryngology clinics. However, the etiology of SSNHL remains unclear. Due to the inaccessibility of the living human inner ear for biopsy, studies investigating the etiology of SSNHL have been performed by analyzing data obtained from examinations using peripheral blood or imaging. We updated the findings obtained from serological, magnetic resonance imaging, genetic, and viral examinations to reveal the etiology of SSNHL. Regarding viral examination, we focused on sensorineural hearing loss associated with coronavirus disease (COVID-19) because the number of correlated reports has been increasing after the outbreak. The updated findings revealed the following three possible mechanisms underlying the development of SSNHL: thrombosis and resulting vascular obstruction in the cochlea, asymptomatic viral infection and resulting damage to the cochlea, and cochlear inflammation and resulting damage to the cochlea. Thrombosis and viral infection are predominant, and cochlear inflammation can be secondarily induced through viral infection or even thrombosis. The findings about sensorineural hearing loss associated with COVID-19 supported the possibility that asymptomatic viral infection is one of the etiologies of SSNHL, and the virus can infect inner ear tissues and directly damage them.

Role of MicroRNAs, Aptamers in Neuroinflammation and Neurodegenerative Disorders

Exploring the microRNAs and aptamers for their therapeutic role as biological drugs has expanded the horizon of its applicability against various human diseases, explicitly targeting the genetic materials. RNA-based therapeutics are widely being explored for the treatment and diagnosis of multiple diseases, including neurodegenerative disorders (NDD). Latter includes microRNA, aptamers, ribozymes, and small interfering RNAs (siRNAs), which control the gene expression mainly at the transcriptional strata. One RNA transcript translates into different protein types; hence, therapies targeted at the transcriptional sphere may have prominent and more extensive effects than alternative therapeutics. Unlike conventional gene therapy, RNAs, upon delivery, can either altogether abolish or alter the synthesis of the protein of interest, therefore, regulating their activities in a controlled and diverse manner. NDDs like Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, Prion disease, and others are characterized by deposition of misfolded protein such as amyloid-ß, tau, α-synuclein, huntingtin and prion proteins. Neuroinflammation, one of the perquisites for neurodegeneration, is induced during neurodegenerative pathogenesis. In this review, we discuss microRNAs and aptamers' role as two different RNA-based approaches for their unique ability to regulate protein production at the transcription level, hence offering many advantages over other biologicals. The microRNA acts either by alleviating the malfunctioning RNA expression or by working as a replacement to lost microRNA. On the contrary, aptamer act as a chemical antibody and forms an aptamer-target complex.

Genetic Polymorphisms in miR-137 and Its Target Genes, TCF4 and CACNA1C, Contribute to the Risk of Bipolar Disorder: A Preliminary Case-Control Study and Bioinformatics Analysis

Accumulating evidence has suggested that miR-137 and its target genes, CACNA1C, and TCF4, are amongst the most robustly implicated genes in psychiatric disorders. This preliminary study is aimed at investigating the effects of genetic variations in miR-137 (rs1625579A/C), TCF4 (rs1261084C/T), and CACNA1C (rs10774053A/G and rs10466907G/T) on BD susceptibility. We recruited 252 BD patients and 213 healthy subjects as the control group. Genotyping was performed using PCR-RFLP and ARMS-PCR methods. Enhanced risk of BD was found under the codominant homozygous, dominant, and allelic models of TCF4 rs1261084C/T, codominant homozygous and allelic models of CACNA1C rs10466907G/T polymorphisms, as well as codominant homozygous, dominant, recessive, and allelic models of the CACNA1C rs10774053A/G. Moreover, both TT/AG/GT/AA and TT/GG/GT/AC genotype combinations strongly increased the risk of BD in the participants. The bioinformatics analyses revealed that rs1261084C/T and rs10466907G/T created and disrupted binding sites of some miRNAs in the 3'-untranslated region of TCF4 and CACNA1C genes. In contrast, the rs10774053A/G created a new binding site for a major splicing factor and might have an effective role in the function of the CACNA1C protein. We have found that all the studied SNPs are positively associated with BD susceptibility. Replicated studies on different ethnicities are required to confirm these findings.

Comparative transcriptome analysis of brain and gonad reveals reproduction-related miRNAs in the giant prawn, Macrobrachium rosenbergii

Macrobrachium rosenbergii (M. rosenbergii), as a species of common prawn, is a delicacy that is consumed all over the world. By interacting with the target gene 3′-untranslated region (3'-UTR), microRNAs (miRNAs) regulate its expression and ultimately participate in the regulation of reproductive development. However, research focusing on miRNA regulation during gonadal development in M. rosenbergii received very little attention. To explore the association between miRNA and reproduction, we performed RNA sequencing (RNA-seq) on brain and gonad organs in male and female M. rosenbergii. A total of 494 miRNAs were obtained in RNA-seq, including 31 and 59 differentially expressed (DE) miRNAs in the brain and gonads, respectively. Furthermore, 9 DE miRNAs were randomly selected from the brain and gonads, and qRT-PCR was conducted to validate the results of RNA-seq. Interestingly, dpu-miR-133 was found to be substantially expressed in the male brain and testis but poorly expressed in the female brain, ovary, and other organs. Analysis of dpu-miR-133 by Targetscan and MiRanda predicted to target 5-HT1. Furthermore, the dual-luciferase reporter assay manifested that dpu-miR-133 can combine with 5-HT1. Overall, our research work provides basic data for further study on the miRNA-mediated regulation of brain, gonad, and reproductive development of study M. rosenbergii.

MicroRNAs and Synaptic Plasticity: From Their Molecular Roles to Response to Therapy

Synaptic plasticity is the ability of synapses to weaken or strengthen over time, in response to changes in the activity of the neurons. It is orchestrated by a variety of genes, proteins, and external and internal factors, especially epigenetic factors. MicroRNAs (miRNAs) are well-acknowledged epigenetic modulators that regulate the translation and degradation of target genes in the nervous system. Increasing evidence has suggested that a number of miRNAs play important roles in modulating various aspects of synaptic plasticity. The deregulation of miRNAs could be associated with pathological alterations in synaptic plasticity, which could lead to different CNS-related diseases. Herein, we provide an update on the role of miRNAs in governing synaptic plasticity. In addition, we also summarize recent researches on the role of miRNAs in drug addiction, and their targets and mechanism of action. Understanding of the way in which miRNAs contribute to synaptic plasticity provides rational clues in establishing the novel biomarkers and new therapeutic strategies for the diagnosis and treatment of plasticity-related diseases and drug addiction.

MicroRNA-29a-3p Regulates SH-SY5Y Cell Proliferation and Neurite Growth through Interaction with PTEN-PI3K/AKT/mTOR Signaling Pathway

The effects of microRNA-29a-3p in the proliferation process of nerve cells are unclear. The purpose of this study is to delve into the regulatory role of microRNA-29a-3p, via interaction with phosphatase and tension homolog (PTEN), in the SH-SY5Y cell proliferation process. Different expressions of microRNA-29a-3p in the SH-SY5Y cells were constructed by transfected miRNA-29a-3p mimic and inhibitor. The effects of cell transfection and the mRNA expressions of PTEN, Akt, and mTOR were detected by qPCR. The expressions of PTEN, Akt, and mTOR protein and the phosphorylation levels of Akt and mTOR were examined using Western blotting. Nerve cell proliferation activity and neurite length of each group were measured and examined by the use of 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2Htetrazolium bromide (MTT), and morphological examination. We observed that the levels of PTEN mRNA and protein were distinctly decreased in the microRNA-29a-3p mimic group, but the expressions of the phosphorylated Akt and mTOR mRNA and protein were distinctly upregulated. In the transfected miRNA-29a-3p inhibitor SH-SY5Y cells, the expressions of miRNA-29a-3p were significantly suppressed; however, the expressions of PTEN gene and protein were significantly enhanced. The expressions of phosphorylated Akt and mTOR in the downregulated microRNA-29a-3p group distinctly were suppressed. The SH-SY5Y cell proliferation activity and neurite length in the upregulated microRNA-29a-3p group increased significantly. Our findings revealed that microRNA-29a-3p could enhance the proliferation activity of SH-SY5Y cells and promote neurite growth by inhibiting the expression of PTEN and regulating PI3K/Akt/mTOR signaling pathway.

Circulating miRNAs as Potential Biomarkers for Patient Stratification in Bipolar Disorder: A Combined Review and Data Mining Approach

Bipolar disorder is a debilitating psychiatric condition that is shaped in a concerted interplay between hereditary and triggering risk factors. Profound depression and mania define the disorder, but high clinical heterogeneity among patients complicates diagnosis as well as pharmacological intervention. Identification of peripheral biomarkers that capture the genomic response to the exposome may thus progress the development of personalized treatment. MicroRNAs (miRNAs) play a prominent role in of post-transcriptional gene regulation in the context of brain development and mental health. They are coordinately modulated by multifarious effectors, and alteration in their expression profile has been reported in a variety of psychiatric conditions. Intriguingly, miRNAs can be released from CNS cells and enter circulatory bio-fluids where they remain remarkably stable. Hence, peripheral circulatory miRNAs may act as bio-indicators for the combination of genetic risk, environmental exposure, and/or treatment response. Here we provide a comprehensive literature search and data mining approach that summarize current experimental evidence supporting the applicability of miRNAs for patient stratification in bipolar disorder.

The impact of single walled carbon nanotubes on the expression of microRNA in zebrafish (Danio rerio) embryos

Objective. Single-walled carbon nanotubes (SWCNTs) are able to cross the blood-brain barrier, penetrate through the cell membrane, and accumulate in the cell nucleus, which purposefully allows their use in the health sciences as imaging probes and drug carriers in the cancer therapy. The aim of this study was to investigate the effect of low doses of SWCNTs on the expression of microRNAs associated with the cell proliferation and the brain development in zebrafish (Danio rerio) embryos. Methods. The zebrafish embryos (72 h post fertilization) were exposed to low doses of SWCNTs (2 and 8 ng/ml of medium) for 24 or 72 h. The microRNAs (miR-19, miR-21, miR-96, miR-143, miR-145, miR-182, and miR-206) expression levels were measured by quantitative polymerase chain reaction analysis. Results. It was found that low doses of SWCNTs elicited dysregulation in the expression of numerous cell proliferation and brain development-related microRNAs (miR-19, miR-21, miR-96, miR-143, miR-145, miR-182, and miR-206) in dose- (2 and 8 ng/ml of medium) as well as malformations in the zebrafish embryos brain development in a time-dependent (24 and 72 h) manner. Conclusion. Taken together, the present data indicate that the low doses of SWCNTs disturbed the genome functions and reduced the miR-19, miR-21, miR-96, miR-143, miR-145, miR-182, and miR-206 expression levels in dose- and time-dependent manners and interrupted the brain development in the zebrafish embryos indicating for both the genotoxic and the neurotoxic interventions.

A Proposed Role for Interactions between Argonautes, miRISC, and RNA Binding Proteins in the Regulation of Local Translation in Neurons and Glia

The first evidence of local translation in the CNS appeared nearly 40 years ago, when electron microscopic studies showed polyribosomes localized to the base of dendritic spines. Since then, local translation has been established as an important regulatory mechanism for gene expression in polarized or functionally compartmentalized cells. While much attention has been placed on characterizing the local transcriptome and regulatory "grammar" directing mRNA localization in neurons and glia, less is understood about how these cells subsequently de-repress mRNA translation in their peripheral processes to produce a rapid translational response to stimuli. MicroRNA-mediated translation regulation offers a possible solution to this question. Not only do miRNAs provide the specificity needed for targeted gene regulation, but association and dynamic interactions between Argonaute (AGO) with sequence-specific RNA-binding proteins may provide a molecular switch to allow for de-repression of target mRNAs. Here, we review the expression and activity of different AGO proteins in miRNA-induced silencing complexes in neurons and glia and discuss known pathways of miRNA-mediated regulation, including activity-dependent pre-miRNA maturation in dendrites. We further detail work on AGO and RNA-binding protein interactions that allow for the reversal of miRNA-mediated translational silencing, and we propose a model for how intercellular communication may play a role in the regulation of local translation.

Spinal cord injury: a study protocol for a systematic review and meta-analysis of microRNA alterations

BACKGROUND

Spinal cord injury (SCI) is a devastating condition with no current neurorestorative treatments. Clinical trials have been hampered by a lack of meaningful diagnostic and prognostic markers of injury severity and neurologic recovery. Objective biomarkers and novel therapies for SCI represent urgent unmet clinical needs. Biomarkers of SCI that objectively stratify the severity of cord damage could expand the depth and scope of clinical trials and represent targets for the development of novel therapies for acute SCI. MicroRNAs (miRNAs) represent promising candidates both as informative molecules of injury severity and recovery, and as therapeutic targets. miRNAs are small, regulatory RNA molecules that are tissue-specific and evolutionarily conserved across species. miRNAs have been shown to represent powerful predictors of pathology, particularly with respect to neurologic disorders.

METHODS

Studies investigating miRNA alterations in all species of animal models and human studies of acute, traumatic SCI will be identified from PubMed, Embase, and Scopus. We aim to identify whether SCI is associated with a specific pattern of miRNA expression that is conserved across species, and whether SCI is associated with a tissue- or cell type-specific pattern of miRNA expression. The inclusion criteria for this study will include (1) studies published anytime, (2) including all species, and sexes with acute, traumatic SCI, (3) relating to the alteration of miRNA after SCI, using molecular-based detection platforms including qRT-PCR, microarray, and RNA-sequencing, (4) including statistically significant miRNA alterations in tissues, such as spinal cord, serum/plasma, and/or CSF, and (5) studies with a SHAM surgery group. Articles included in the review will have their titles, abstracts, and full texts reviewed by two independent authors. Random effects meta-regression will be performed, which allows for within-study and between-study variability, on the miRNA expression after SCI or SHAM surgery. We will analyze both the cumulative pooled dataset, as well as datasets stratified by species, tissue type, and timepoint to identify miRNA alterations that are specifically related to the injured spinal cord. We aim to identify SCI-related miRNA that are specifically altered both within a species, and those that are evolutionarily conserved across species, including humans. The analyses will provide a description of the evolutionarily conserved miRNA signature of the pathophysiological response to SCI.

DISCUSSION

Here, we present a protocol to perform a systematic review and meta-analysis to investigate the conserved inter- and intra-species miRNA changes that occur due to acute, traumatic SCI. This review seeks to serve as a valuable resource for the SCI community by establishing a rigorous and unbiased description of miRNA changes after SCI for the next generation of SCI biomarkers and therapeutic interventions.

TRIAL REGISTRATION

The protocol for the systematic review and meta-analysis has been registered through PROSPERO: CRD42021222552 .

Investigating miRNA-mRNA interactions and gene regulatory networks from VTA dopaminergic neurons following perinatal nicotine and alcohol exposure using Bayesian network analysis

MicroRNAs play an important role in gene regulation for many biological systems, including nicotine and alcohol addiction. However, the underlying mechanism behind miRNAs and mRNA interaction is not well characterized. Microarrays are commonly used to quantify the expression levels of mRNAs and/or miRNAs simultaneously. In this study, we performed a Bayesian network analysis to identify mRNA and miRNA interactions following perinatal exposure to nicotine and/or alcohol. We utilized three sets of microarray data to predict the regulation relationship between mRNA and miRNAs. Following perinatal alcohol exposure, we identified two miRNAs: miR-542-5p and miR-874-3p, that exhibited a strong mutual influence on several mRNA in gene regulatory pathways, mainly Axon guidance and Dopaminergic synapses. Finally, we confirmed our predicted addiction pathways based on the Bayesian network analysis with the widely used Kyoto Encyclopedia of Genes and Genomes (KEGG)-based database and identified comparable relevant miRNA-mRNA pairs. We believe the Bayesian network can provide insight into the complexity biological process related to addiction and can potentially be applied to other diseases.

Ketamine enhances dopamine D1 receptor expression by modulating microRNAs in a ketamine-induced schizophrenia-like mouse model

The abnormal expression of the dopamine D1 receptor (DRD1) may be associated with schizophrenia. MicroRNAs (miRNAs) can post-transcriptionally regulate DRD1 expression. Here, we established a ketamine-induced schizophrenia-like behavior mouse model and investigated the changes in miR-15a-3p, miR-15b-3p, miR-16-1-3p, and DRD1 in response to ketamine. Administration of high-dose ketamine for seven consecutive days to mice simulated the main symptoms of schizophrenia. The mice exhibited increasing excitability and autonomous activity and reduced learning and memory, including spatial memory. Moreover, ketamine decreased miR-15a-3p, miR-15b-3p, and miR-16-1-3p expression levels in the prefrontal cortex (PFC) and miR-16-1-3p expression in the hippocampus, whereas DRD1 expression increased in these brain regions. In HT22 mouse hippocampal neuronal cells, ketamine induced a dose-dependent increase of endogenous DRD1, which was partially attenuated by a combination of miR-15b-3p and miR-16-1-3p mimics. Indeed, the miR-15b-3p and miR-16-1-3p mimics could significantly inhibit endogenous DRD1expression. We identified +72 to +78 bp (TGCTGCT) of the DRD1 3'UTR as the core regulatory region recognized by the target miRNAs. In summary, we developed a ketamine-induced schizophrenia-like behavior mouse model and found that ketamine inhibited the levels of miR-15a-3p, miR-15b-3p, miR-16-1-3p and increased DRD1 expression in mice.

Differential expression profiles of microRNAs in musk gland of unmated and mated forest musk deer (Moschus berezovskii)

Background

The formation of musk is a complex biophysical and biochemical process that change with the rut of male forest musk deer. We have reported that the mating status of male forest musk deer might result to the variations of chemical composition and microbiota of musk and its yields. Critical roles for microRNAs (miRNAs) of multi-tissues were profiled in our previous study; however, the role for miRNAs of the musk gland remains unclear in this species.

Methods

In this study, we used Illumina deep sequencing technology to sequence the small RNA transcriptome of unmated male (UM) and mated male (UM) of Chinese forest musk deer.

Results

We identified 1,652 known miRNAs and 45 novel miRNAs, of which there were 174 differentially expressed miRNAs between UM and MM. chi-miR-21-5p, ipu-miR-99b and bta-miR-26a were up-regulated in UM among the 10 most differentially expressed miRNAs. Functional enrichment of the target genes showed that monosaccharide biosynthetic process, protein targeting, cellular protein catabolic process enriched higher in MM. Meanwhile, structural molecule activity, secretion by cell, regulated exocytosis and circulatory system process enriched more in UM, hinting that the formation of musk in UM was mediated by target genes related to exocytosis. The miRNA-mRNA pairs such as miR-21: CHD7, miR143: HSD17B7, miR-141/200a: Noc2 might involve in musk gland development and musk secretion, which need to be verified in future study.

The role of the microRNA regulatory network in Alzheimer's disease: a bioinformatics analysis

INTRODUCTION

Alzheimer's disease (AD) is a neurodegenerative disease which presents with an earlier age of onset and increased symptom severity. The objective of this study was to evaluate the relationship between regulation of miRNAs and AD.

MATERIAL AND METHODS

We completed a bioinformatic analysis of miRNA-AD studies through multiple databases such as TargetScan, Database for Annotation, Visualization and Integrated Discovery (DAVID), FunRich and String and assessed which miRNAs are commonly elevated or decreased in brain tissues, cerebrospinal fluid (CSF) and blood of AD patients. All identified articles were assessed using specific inclusion and exclusion criteria.

RESULTS

MiRNAs related to AD of twenty-eight studies were assessed in this study. A wide range of miRNAs were up-regulated or down-regulated in tissues of AD patients' brain, blood and CSF. Twenty-seven differentially dysregulated miRNAs involved in amyloidogenesis, inflammation, tau phosphorylation, apoptosis, synaptogenesis, neurotrophism, neuron degradation, and activation of cell cycle entry were identified. Additionally, our bioinformatics analysis identified the top ten functions of common miRNAs in candidate studies. The functions of common up-regulated miRNAs primarily target the nucleus and common down-regulated miRNAs primarily target transcription, DNA-templated.

CONCLUSIONS

Comprehensive analysis of all miRNA studies reveals cooperation in miRNA signatures whether in brain tissues or in CSF and peripheral blood. More and more studies suggest that miRNAs may play crucial roles as diagnostic biomarkers and/or as new therapeutic targets in AD. According to biomarkers, we can identify the preclinical phase early, which provides an important time window for therapeutic intervention.

MicroRNAs Regulate Cell Cycle and Cell Death Pathways in Glioblastoma

Glioblastoma (GBM), a grade IV brain tumor, is known for its heterogenicity and its resistance to the current treatment regimen. Over the last few decades, a significant amount of new molecular and genetic findings has been reported regarding factors contributing to GBM’s development into a lethal phenotype and its overall poor prognosis. MicroRNA (miRNAs) are small non-coding sequences of RNA that regulate and influence the expression of multiple genes. Many research findings have highlighted the importance of miRNAs in facilitating and controlling normal biological functions, including cell differentiation, proliferation, and apoptosis. Furthermore, miRNAs’ ability to initiate and promote cancer development, directly or indirectly, has been shown in many types of cancer. There is a clear association between alteration in miRNAs expression in GBM’s ability to escape apoptosis, proliferation, and resistance to treatment. Further, miRNAs regulate the already altered pathways in GBM, including P53, RB, and PI3K-AKT pathways. Furthermore, miRNAs also contribute to autophagy at multiple stages. In this review, we summarize the functions of miRNAs in GBM pathways linked to dysregulation of cell cycle control, apoptosis and resistance to treatment, and the possible use of miRNAs in clinical settings as treatment and prediction biomarkers.

MicroRNA-124 Promotes Singapore Grouper Iridovirus Replication and Negatively Regulates Innate Immune Response

Viral infections seriously affect the health of organisms including humans. Now, more and more researchers believe that microRNAs (miRNAs), one of the members of the non-coding RNA family, play significant roles in cell biological function, disease occurrence, and immunotherapy. However, the roles of miRNAs in virus infection (entry and replication) and cellular immune response remain poorly understood, especially in low vertebrate fish. In this study, based on the established virus-cell infection model, Singapore grouper iridovirus (SGIV)-infected cells were used to explore the roles of miR-124 of Epinephelus coioides, an economically mariculture fish in southern China and Southeast Asia, in viral infection and host immune responses. The expression level of E. coioides miR-124 was significantly upregulated after SGIV infection; miR-124 cannot significantly affect the entry of SGIV, but the upregulated miR-124 could significantly promote the SGIV-induced cytopathic effects (CPEs), the viral titer, and the expressions of viral genes. The target genes of miR-124 were JNK3/p38α mitogen-activated protein kinase (MAPK). Overexpression of miR-124 could dramatically inhibit the activation of NF-κB/activating protein-1 (AP-1), the transcription of proinflammatory factors, caspase-9/3, and the cell apoptosis. And opposite results happen when the expression of miR-124 was inhibited. The results suggest that E. coioides miR-124 could promote viral replication and negatively regulate host immune response by targeting JNK3/p38α MAPK, which furthers our understanding of virus and host immune interactions.

Long transcripts minus touchdown qPCR (LTMT-qPCR): a simplified and convenient method for the screening and quantification of microRNA profiles

Due to the short length and differences in abundance of microRNAs, microRNA profile screening and quantification is challenging. In this study, we found that size selection magnetic beads could be employed to easily and efficiently remove long RNA transcripts. After removing the long transcripts, the remaining small RNAs could be concentrated and then reverse-transcribed using universal stem-loop primers (USLP), with six randomized nucleotides at the 3' end region. The efficiency of reverse transcription decreased when the number of randomized nucleotides was reduced. In addition, we found that touchdown qPCR improved microRNA profile detection, with lower C_T values and better detection efficiency than the regular qPCR protocol, especially for those low-abundance microRNAs. Finally, we incorporated these observations to create a new protocol we named long transcripts minus touchdown qPCR (LTMT-qPCR). We performed a side-by-side comparison of LTMT with USLP and traditional stem-loop primer (TSLP) protocols. We found that LTMT has higher detection efficiency than USLP, especially for the detection of low-abundance microRNAs. Although LTMT was equivalent to TSLP in terms of microRNA profile detection, LTMT is more convenient, user-friendly, and cost-effective. Taken together, the present data indicate that LTMT is a simple, rapid, and user-friendly approach that has higher precision, accuracy, and sensitivity than the previously described methods, making it more suitable for microRNA profile screening and quantification.

Posttranscriptional modulation of KCNQ2 gene expression by the miR-106b microRNA family

MicroRNAs (miRNAs) have recently emerged as important regulators of ion channel expression. We show here that select miR-106b family members repress the expression of the KCNQ2 K⁺ channel protein by binding to the 3'-untranslated region of KCNQ2 messenger RNA. During the first few weeks after birth, the expression of miR-106b family members rapidly decreases, whereas KCNQ2 protein level inversely increases. Overexpression of miR-106b mimics resulted in a reduction in KCNQ2 protein levels. Conversely, KCNQ2 levels were up-regulated in neurons transfected with antisense miRNA inhibitors. By constructing more specific and stable forms of miR-106b controlling systems, we further confirmed that overexpression of precursor-miR-106b-5p led to a decrease in KCNQ current density and an increase in firing frequency of hippocampal neurons, while tough decoy miR-106b-5p dramatically increased current density and decreased neuronal excitability. These results unmask a regulatory mechanism of KCNQ2 channel expression in early postnatal development and hint at a role for miR-106b up-regulation in the pathophysiology of epilepsy.

The promise of microRNA-based therapies in Alzheimer's disease: challenges and perspectives

Multi-pathway approaches for the treatment of complex polygenic disorders are emerging as alternatives to classical monotarget therapies and microRNAs are of particular interest in that regard. MicroRNA research has come a long way from their initial discovery to the cumulative appreciation of their regulatory potential in healthy and diseased brain. However, systematic interrogation of putative therapeutic or toxic effects of microRNAs in (models of) Alzheimer's disease is currently missing and fundamental research findings are yet to be translated into clinical applications. Here, we review the literature to summarize the knowledge on microRNA regulation in Alzheimer's pathophysiology and to critically discuss whether and to what extent these increasing insights can be exploited for the development of microRNA-based therapeutics in the clinic.

Comparative analysis of the miRNA-mRNA regulation networks in turbot (Scophthalmus maximus L.) following Vibrio anguillarum infection

MicroRNAs could not only regulate posttranscriptional silencing of target genes in eukaryotic organisms, but also have positive effect on their target genes as well. These microRNAs have been reported to be involved in mucosal immune responses to pathogen infection in teleost. Therefore, we constructed the immune-related miRNA-mRNA networks in turbot intestine following Vibrio anguillarum infection. In our results, 1550 differentially expressed (DE) genes and 167 DE miRNAs were identified. 113 DE miRNAs targeting 89 DE mRNAs related to immune response were used to construct miRNA-mRNA interaction networks. Functional analysis showed that target genes were associated with synthesis and degradation of ketone bodies, mucin type O-Glycan biosynthesis, homologous recombination, biotin metabolism, and intestinal immune network for IgA production that were equivalent to the function of IgT and IgM in fish intestine. Finally, 10 DE miRNAs and 7 DE mRNAs were selected for validating the accuracy of high-throughput sequencing results by qRT-PCR. The results of this study will provide valuable information for the elucidation of the regulation mechanisms of miRNA-mRNA interactions involved in disease resistance in teleost mucosal immune system.

Homeostatic scaling is driven by a translation-dependent degradation axis that recruits miRISC remodeling

Homeostatic scaling in neurons has been attributed to the individual contribution of either translation or degradation; however, there remains limited insight toward understanding how the interplay between the two processes effectuates synaptic homeostasis. Here, we report that a codependence between protein synthesis and degradation mechanisms drives synaptic homeostasis, whereas abrogation of either prevents it. Coordination between the two processes is achieved through the formation of a tripartite complex between translation regulators, the 26S proteasome, and the miRNA-induced silencing complex (miRISC) components such as Argonaute, MOV10, and Trim32 on actively translating transcripts or polysomes. The components of this ternary complex directly interact with each other in an RNA-dependent manner. Disruption of polysomes abolishes this ternary interaction, suggesting that translating RNAs facilitate the combinatorial action of the proteasome and the translational apparatus. We identify that synaptic downscaling involves miRISC remodeling, which entails the mTORC1-dependent translation of Trim32, an E3 ligase, and the subsequent degradation of its target, MOV10 via the phosphorylation of p70 S6 kinase. We find that the E3 ligase Trim32 specifically polyubiquitinates MOV10 for its degradation during synaptic downscaling. MOV10 degradation alone is sufficient to invoke downscaling by enhancing Arc translation through its 3' UTR and causing the subsequent removal of postsynaptic AMPA receptors. Synaptic scaling was occluded when we depleted Trim32 and overexpressed MOV10 in neurons, suggesting that the Trim32-MOV10 axis is necessary for synaptic downscaling. We propose a mechanism that exploits a translation-driven protein degradation paradigm to invoke miRISC remodeling and induce homeostatic scaling during chronic network activity.

MicroRNAs in the Onset of Schizophrenia

Mounting evidence implicates microRNAs (miRNAs) in the pathology of schizophrenia. These small noncoding RNAs bind to mRNAs containing complementary sequences and promote their degradation and/or inhibit protein synthesis. A single miRNA may have hundreds of targets, and miRNA targets are overrepresented among schizophrenia-risk genes. Although schizophrenia is a neurodevelopmental disorder, symptoms usually do not appear until adolescence, and most patients do not receive a schizophrenia diagnosis until late adolescence or early adulthood. However, few studies have examined miRNAs during this critical period. First, we examine evidence that the miRNA pathway is dynamic throughout adolescence and adulthood and that miRNAs regulate processes critical to late neurodevelopment that are aberrant in patients with schizophrenia. Next, we examine evidence implicating miRNAs in the conversion to psychosis, including a schizophrenia-associated single nucleotide polymorphism in MIR137HG that is among the strongest known predictors of age of onset in patients with schizophrenia. Finally, we examine how hemizygosity for DGCR8, which encodes an obligate component of the complex that synthesizes miRNA precursors, may contribute to the onset of psychosis in patients with 22q11.2 microdeletions and how animal models of this disorder can help us understand the many roles of miRNAs in the onset of schizophrenia.

Label-free and sensitive MiRNA detection based on turn-on fluorescence of DNA-templated silver nanoclusters coupled with duplex-specific nuclease-assisted signal amplification

A novel strategy for microRNAs (miRNAs) detection has been developed utilizing duplex-specific nuclease-assisted signal amplification (DSNSA) and guanine-rich DNA-enhanced fluorescence of DNA-templated silver nanoclusters (AgNCs). The combination between target miRNA, DSNSA, and AgNCs is achieved by the unique design of DNA sequences. Target miRNA opens the hairpin structure of the Hairpin DNA probe (HP) by hybridizing with the HP and initiates the duplex-specific nuclease-assisted signal amplification (DSNSA) reaction. The DSNSA reaction generates the release of the guanine-rich DNA sequence, which can turn on the fluorescence of the dark AgNCs by hybridizing with the DNA template of the dark AgNCs. The fluorescence intensity of AgNCs corresponds to the dosage of the target miRNA. This is measured at 630 nm by exciting at 560 nm. The constructed method exhibits a low detection limit (~8.3 fmol), a great dynamic range of more than three orders of magnitude, and excellent selectivity. Moreover, it has a good performance for miR-21 detection in complex biological samples. A novel strategy for microRNAs (miRNAs) detection has been developed utilizing duplex-specific nuclease-assisted signal amplification (DSNSA) and guanine-rich DNA-enhanced fluorescence of DNA-templated silver nanoclusters (AgNCs).

Toxic and Teratogenic Effects of Prenatal Alcohol Exposure on Fetal Development, Adolescence, and Adulthood

Prenatal alcohol exposure (PAE) can have immediate and long-lasting toxic and teratogenic effects on an individual’s development and health. As a toxicant, alcohol can lead to a variety of physical and neurological anomalies in the fetus that can lead to behavioral and other impairments which may last a lifetime. Recent studies have focused on identifying mechanisms that mediate the immediate teratogenic effects of alcohol on fetal development and mechanisms that facilitate the persistent toxic effects of alcohol on health and predisposition to disease later in life. This review focuses on the contribution of epigenetic modifications and intercellular transporters like extracellular vesicles to the toxicity of PAE and to immediate and long-term consequences on an individual’s health and risk of disease.

Research Progress on the Correlation Between Epigenetics and Schizophrenia

Purpose of the Review

Nowadays, the incidence of schizophrenia is noticeably increased. If left undiagnosed and untreated, it will lead to impaired social functions, repeated hospital admissions, decline in quality of life and life expectancy. However, the diagnosis of schizophrenia is complicated and challenging. Both genetic and environmental factors are considered as important contributors to the development and progression of this disorder. The environmental factors have been linked to changes in gene expression through epigenetic modulations, which have raised more and more research interests in recent years. This review article is to summarize the current findings and understanding of epigenetic modulation associated with pathogenesis of schizophrenia, aiming to provide useful information for further research in developing biomarkers for schizophrenia.

Recent Findings

Three major types of epigenetic modulations have been described in this article. Firstly, both DNA hypermethylation and hypomethylated have been associated with schizophrenia via analyzing post-mortem brain tissues and peripheral blood of patients. Specific changes of non-coding RNAs, particularly microRNAs and long-chain non-coding RNAs, have been observed in central and peripheral samples of schizophrenia patients, indicating their significant diagnostic value for the disease, and may also potentially predict treatment response. The correlation between histone modification and schizophrenia, however, is largely unclear.

Summary

Epigenetic modulations, including DNA methylation, ncRNA transcriptional regulation and histone modification, play an important role in the pathogenesis of schizophrenia. Therefore, tests of these epigenetic alterations may be utilized to assist in the diagnosis and determination of strategies of individualized treatment in clinical practice.

Inhibition of miR-134-5p protects against kainic acid-induced excitotoxicity through Sirt3-mediated preservation of mitochondrial function

Epilepsy is a neurological disorder which is characterized by brain hyper-excitability and manifests as seizure. Due to its complicated pathogenesis, treatment for epilepsy still remains a huge challenge for neurology in the whole world. MciroRNA-134 (miR-134) is one kind of miRNAs which was firstly found abundant in synapses. In this study, we tried to unveil the role of inhibiting MciroRNA-134-5p (miR-134-5p) in excitotoxicity induced by kainic acid (KA) in the hippocampal neurons (HT22) cells. The results showed that treatment of KA increased the expression of miR-134-5p significantly and caused marked neuron excitotoxicity, evidenced by risen cell death rate, higher LDH release and aggravated cell viability. After suppressing miR-134-5p expression via transfecting HT22 cells with miR-134-5p antisense (Anti-134), cell viability was promoted obviously, along with decreased LDH release and cell death rate. In addition, KA-induced lipid peroxidation, cytochrome c release and mitochondrial ROS generation were also attenuated by Anti-134. The level of Sirtuin 3 (Sirt3) and its downstream antioxidant enzymes, such as mitochondrial superoxide dismutase 2 (SOD2), isocitrate dehydrogenase 2 (IDH2) and glutathione peroxidase (GSH-Px), were significantly higher in Anti-134 group compared with the control and scramble group. After inhibiting Sirt3 expression with SiRNA targeting Sirt3 (Si-Sirt3) and 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP), the positive role of Anti-134 was apparently reversed. In conclusion, this research highly suggests that inhibition of miR-134-5p could protect neurons from KA-induced excitotoxicity through Sirt3-mediated preservation of mitochondrial function.